engine oil turned to foam

[Burton58]

1968 mopar 318 v8, inboard boat

put the boat in today and the engine oil turned to foam and blew the breather right out of the valve cover. i'm thinking it HAS to be water in the oil (it's a boat there's a lot of water around) but the question is from where and how.. motor was rebuilt not long ago and has new heads, never overheated including today. i guess this is more of a curiousity thread since i've seen engine oil turn milkshake-like but never spewing foam all over the engine compartment. any thoughts?

[clean4drxj]

any cracks in the heads or anything.. where was this motor before?

[ct67_72]

does it have wet exhaust or wet manifolds?

[clean4drxj]

does it have wet exhaust or wet manifolds?

These do tend to rust.. ask me how I know

[Burton58]

any cracks in the heads or anything.. where was this motor before?

motor has always been in the boat, rebuilt not long ago

does it have wet exhaust or wet manifolds?

well the cooling system kinda is the exhaust haha, so that's hard to tell

[DrThunder]

Ive never seen foamy oil come out of the engine before but having too much oil in the engine will cause the oil to foam and lose oil pressure. I suppose if you had wayyyy too much oil it may make its way out. Just something to check and rule out quickly.

[ninetysix-ex-jay]

Check the risers it's not unhxcommon for the water jacket to rust through

[Burton58]

Ive never seen foamy oil come out of the engine before but having too much oil in the engine will cause the oil to foam and lose oil pressure. I suppose if you had wayyyy too much oil it may make its way out. Just something to check and rule out quickly.

Check the risers it's not unhxcommon for the water jacket to rust through

Thanks guys

[ninetysix-ex-jay]

I'm going to guess its a raw water cooled boat.

The risers are located behind the exhaust manifold and raise up a bit so water doesn't in through the exhaust into the motor. On the outside of the riser you have the water jacket and inside is the exhaust. This is so the water has a place to go and that you dont overheat the exhaust manifold. If they've been in for a while, trust me, they will be a bitch to remove. Salt water and heat are nightmares to these parts. If you unbolt it with the boat in the water, you NEED TO KEEP THE EXHAUST OUTLET AFTER THE RISER ABOVE THE WATERLINE! If not, you won't have a boat in the morning. It can be done in the water, we used to do it all the time at the marina when I worked there but be smart about it

[Burton58]

Awesome jon thanks. Yes its raw water cooled, fresh water only. Its an 18' century buccaneer if that matters. Anyway i was hoping we wouldn't have to pull the motor for this so that's good. Its in the boathouse on a lift so there won't be any water in the exhaust. Gonna start tearing it down after we clean the mess it made all over

[ninetysix-ex-jay]

Any time. Call me if youre in a jam